Pump



March 22, 1938. F. BURGHAUSER 2,111,883

PUMP

Filed Feb. 5, 1957 s Sheets-sheet 1 March 22, 1938.

F. BURGHAUSER PUMP Filed Feb. 3, 1937 5 Sheets-Sheet 2 I/vvs/vIoR A'rTY March 22, 1938.

F. BURGHAUSER PUMP Filed Feb. 3, 1957 3 Sheets-Sheet 3 TNVEN To Patented Mar. 22, 1938 UNITED STATES PATENTIOFFICE I PM "I Franz Burghauser, Nuremberg, Germany Application February 3, 1937, Serial No. 123,913

In Germany April 17, 1936 a f'i Claims.

screw-spindles and has-for its general object to provide an improved lubrication for such pumps as well as an improved arrangement of the moving parts thereof with a view of removing all objectionabl'e stresses therefrom.

It is known that the screw-spindles of pumps ing parts of the pump at the expense of its efllciency.

In case high pressures are used'in pumps of the present kind, and more especially in case of high speeds of rotation, the bearings for the screw-spindles are being. subjectto' large mechanical strains. In addition to this a bending of the screw-spindles may arise owing to the high pressure employed, such bending rendering it necessary'to provide an undesirably large play between the screw-spindles and the casing in '25 order to attain full safety of operation. By this,

however, the volumetric as 'well as the total emciency of the pump will be reduced to an undesirable degree.

A further disadvantage'of pumps of this -kind consists therein that owingto the high oil pressures the bearing surfaces will be subject to. considerable strains owing to excessive lateral pressures that are one-sidedly imposed onto said sur- 35 faces, this resulting likewise. in an undesirably large wear of the bearings.

By my invention, now, the aforementioned disadvantages are fully and successfully avoided and, in addition to this-a number of valuable advantages are attained so that it will be possible to not only render the operation of the pumps absolutely reliable butalso toincrease at the same time. the efficiency of the pump to a quite considerable extent and, in addition, to essentially 5 simplify the mechanical construction of the All these advantages connected with the pump forming part of my present invention will be attained on the one hand in that instead of the 50 heretofore necessary large play in the bearings and between the surfaces and edges of the casing and the spindles, the outer-diameters of the spindles are dimensioned to reduce said play'to the absolutely necessary minimumrwhile in ad- 55 dition to this the threads of the spindles are ing liquid will be drawn into this gap in accord- I effectively be utilized to successfully serve, so-to- This invention relates to pumps operating with made of slightly conical conformation at their outer diameters on the side towards the pressurespace of the pumps. By so arranging the pump I attain that during contacting of the screw-spindles with the interior wall of the pump casing 5 the heretofore sharp edge of the threads which move helically forward in axial direction along the surface of the casing will always be surrounded-by liquid, thus enabling a lubricated metallic contact to be maintained between 10 surfaces relatively moving with respect to each other and in spite of this avoiding any corrosion and wear of said surfaces. By reason of the aforementioned slightly-conical conformation of the spindles at the outer diameter of their threads in accordance with my invention. the

effect will be'attained that owing to the slight conical gap thus produced between the conical outer surface of the screw-spindles and the casance with the principles of the, theory of hydro- 2o dynamic lubrication and the pressure of said liquid raised to a considerable value. In this manner, an actual metallic non-lubricated contact between the outer surfaces of the spindles and the inner surface of thecasing will be positively avoided with the greatest degree of certainty during operation of the pump. Owing to this, moreover, the bofe in the pump casing will speak, as an additional bearing for the screwspindles of the pump, thus eiiectively releasing the main bearings from undesirable strain. According to my invention it will even be possible to construct the side-spindle without employing special bearings therefor, if the thread of said spindle is givena conical conformation in accordance with my'invention, the said spindle, now, together with the-bore of the casing forming a bearing. Preferably, in this case the sidespindles are provided with a thread of greatest possible width and a rather narrow gro'ove between said thread in order toattain a, greatest possible bearing surface between these spindles and the pump T As a further result of my invention the bear-- ings constructed in-this manner will partly be released from strains which may'eventually arise. In particular, such release from strains" is further facilitated according to my invention by. providing a recess having a proper size and opening'towards the suction side .of the pump, this recess having the effect of unevenly distributing the oil pressure in the bearing, thus rendering it possible to equalize or counter-act the spindle- 55 its value in the suction-space.

pressure in the bearlngs by an appropriate oilpressure, with the result that said side-spindle.

will so-to-speak be kept in a floating condition within its bearing.

In the accompanying drawings, I have illustrated an exempliiication of pumps constructed in accordance with my invention wherein:

Figures 1 and 2 are fragmentary longitudinal sectional views taken at right angles to each other through a screw spindle pump constructed in accordance with my invention, the spindles being shown in elevation;

Figure 3 is a fragmentary transverse sectional view thereof;

Figures 4 and 5 are longitudinal sectional views taken at right angles to each other through a complete screw spindle pump embodying my invention;

Figure 6 is a transverse sectional view therethrough;

Figure 7 is an end elevation thereof;

Figures 8 and 9 are views similar to Figures 4 and 5 but illustrating a slightly modified form of my invention;

Figure 10 is a transverse sectional view through Figure 8;

Figure 11 is an end elevation of Figure 9; and Figure 12 is afragmentary view partly in elevation and partly in section showing a slight modification of the screw spindle;

Referring more particularly to the drawings, the main spindle A and the side-spindle-B according to my invention are of slightly conical conformation along the periphery of the spindle threads, the so provided peripheral surfaces of the spindles tapering towards the pressure-space of the pump. The spindle, threads are thus of tively. for both spindles, said recesses being of such conformation that the bearing forces arising by action of the lateral spindle pressures during operation of the pump are equalized or counteracted by the oil-pressure in the pump.

From the pressure-space of the pump oil is supplied to the bearing space 2' through the bore h in the main spindle A, said oil further flowing through the play in the bearings G and F towards the suction space of the pump, the pressure being reduced from its value in the pressure-space to Froin the triangular diagrams I, 2; 3 and 5, 6, 1 shown in Fig. 2, it may be seen that the line 23 and the line 6 -1 represent the pressure-drop alongside the two lines representing the bearing-surfaces. From these diagrams it may further be seen that by reason of the recess d the pressure at the point 6 has already been reduced to the value of the pressure on the suction-side'of the pump. From this it follows that the oil-pressure on either side. of the bearing is of different amount due to the action of said recess d; more particularly, on the side of the bearing opposite said recess there prevailsv an oil pressure which is larger by an armunt'represented by the surface of the friangle, 2, 3, 4, in which 1-4 has been madeequal to 5'6. By properly dimensioning and position- I ing the recesses 11, e, ,f, and g according to my invention, it will be possible to counteract the respective spindle-pressures s1, s2 etc. by a proper excess of oil-pressures 01, 02 etc. in the bearings, thus fully or partly counteracting said lateral spindle-pressures in the.bearlngs by oil-pressure and to relieve said bearings to such an extent from strains that the spindles will be in an ideal condition of floating.

Figs. 4 to .6 show in proper sections the general assembly of a pump with screw-spindles, while Fig. 7 shows the bearing on the pressureside of the pump in view. The main spindle A and the side-spindle B show on their side towards the pressure-space the slightly conical conformation of their threads at their outer diameters at a and b and the slightly conical interstice into which during rotation of the pump liquid will be drawn and subjected to high pressures so that any bare metallic contact between parts sliding upon each other will be avoided with certainty. Besides, the recesses d, e, f and g are provided in the bearing surfaces of the slightly,conical surfaces, the same as .in the constructions shown in the former figures.

In contradistlnction to the constructions shown in Figs. 1 -'7, according to Figs. 8, 9, and 10, the side-spindle B is not driven by obliquely toothed pinions but by the lateral surfaces of the threads on the spindles in connection with a novel friclion-bearing which in addition serves to secure the side-spindle B in proper axial position. At the end of the shai. of the side-spindle B there are mounted for this purpose two friction collars q and 12, while the shaft of the main spindle A carries a friction collar 1' having conical sidesurfaces engaging between the facing conical side-surfaces of either of said collars q and p on said side-spindle.

During operation of the pump the collar r on the main spindle A will be rolling along said collars q and p on the side-spindle B, all of said collars being of even average actuating diameters,

the rolling motion being thus partly a sliding or frictional motion. In this manner the collar 1' is being pressed against the-collars q and p in rolling and partly sliding engagement therewith by action of the axial forces and of the but slightly conically tapering lateral surfaces of all of said collars. In accordance with the theory of hydrodynamics, in spite of the relatively small contact-surfaces between said collar r and said collars q and p quite considerable axial pressures may safely be counteracted by oil-pressure without the slightest wear of any of the operating parts even after long 'and continuous serviceof the pump.

The axial thrust of the main spindle A is being counteracted in known manner by a journal which is provided at one end of said spindle as shown in Figs. 1 and 2,"pressure-oil being supplied to said journal through the bore h from the pressurespace of the pump, said oil being pressed into several'conically tapering transverse grooves provided at the contacting bearing surfaces as shown particularly in Figures 1 and 2. The axial pressure of the side-spindle B is transmitted by way of the aforesaid collars p, q and r to the main spindle A and, in addition, taken up by the bearing ring a; at the journal, of the main-spindle. In the present case the bore of the casing serves as a bearing for the side-spindle B along its conical 1 outer surface andthus secures said side-spindle in described herein and shown in the drawings are not-the only possible constructions, speaking in the sense of my invention. Thus,

for instance,- the screw-spindles may also be provided on both sides of-the thread at its outer periphery with the aforementioned'siightly conical surfaces a, as

shown in Fig; 12;.which may; for instance, be of importance forthe reversing of the pump and the like, in order to attain proper operation of the latter in either direction of rotation.

Iclaimzw j ump including a casing, a of screw spindles, to wit: a main and a side spindle having their threads in engagement witheach'other and mounted iii said casing-with a-slight play between their outer'slu'faces and the inner surface of said casing, and a slightly conical surface at the perlpheryof the threads of said spindles, to provide a slightly conical gap for lubricating liquid between said spindles and said casing.

sauce 2. A pump as specified by claim 1, in which the slightly conical surfaces are provided at one side only of said threads.

r 3. A pump as specified by claim 1, in which said slightly conical surfaces are provided on both sides of said threads.

j 4. A pump as specified sure liquid from the pressure space of said pump, recesses in said bearing surfaces opening towards the suction side of said pump, said recesses being positioned at the. side opposite to the radial spindle-pressures.

by claim 1, including bearing surfaces adapted to be lubricated by pres- 5. A pump as spec fiedby claim 1, in which the side-spindle is mounted without end-bearings within the bore of said casing, said bore adapted .to serve as'the bearing surface for said spindle.

6. A pump asspecifledby claim 1, in which the side-spindle is mounted without end-bearings within the bore of said casing-, sald bore adapted to serve as the bearing surface for said spindle,

said pump including a friction bearing inter posed between both spindles.

'l. A pump as specified by claim 1, in which the side-spindle is mounted without end-bearings within the bore of said casing, said bore adapted to serve as the bearing surface for said spindle, said pump 'including a friction bearing interposed betweenboth spindles, said friction bearing including a friction member on said main spindle, said friction member engaging with a pair of friction-members on, the sde-spindle, all

of said friction members having sligh conical friction surfaces. FRANZ BURGHAUSER. 

